Like most other Leviathans, Tamamitsune have a long, slender body. However, it is one of the few Leviathans to actually have fur on its body. This fur covers its chest, underbelly, legs and tail. Its scales are light colored and resemble those of a fish. Its head has a long snout and is beautifully adorned by many fin-like appendages. These fins are pink with yellow markings, and they can also be seen on its back and tail. Its feet are said to be quite different from other Leviathans and allow Tamamitsune to move swiftly on land.
Tamamitsune are rather calm in nature until provoked. They prefer to be left alone resting near large bodies of water, while covered in their special secretions. They prefer to avoid confrontations; however they will defend themselves if need be. Once a threat has left, Tamamitsune won't chase after the threat but will instead let it go. Though Tamamitsune are usually calm, they are known to turn aggressive during Breeding Season. Tamamitsune become aggressive or even berserk during their Breeding Season. In this season, it is not a good idea to go fishing from them being known to injure people due to their blind rage.
A Tamamitsune's most unique adaption is its ability to produce bubbles. It is able to produce the bubbles by using special fluid secretions, produced from its own body along with water, and rubbing its hairs in the secretions. These stiff yet soft purple hairs are found on its chest, tail, legs, and sides. The hairs are used for sliding on the fluids it produces, spreading the fluids, and even using the fluids to produce more bubbles. Tamamitsune can also breath these bubbly fluids from its mouth. It is known to use the bubbles it produces both offensively and defensively in battle. It uses the bubbles to help it move faster and to make it more flexible in battle, while simultaneously impeding the movement of any foes. In order to stop itself quickly while moving, A Tamamitsune has special hook-like claws that allow it to stop sliding quickly to face threats and not leave itself open. Despite Tamamitsune's strange appearance, the fins it has actually act as receptors for detecting the presence of predators and prey coming through vibrations in the secretions. Like a snake, Tamamitsune's teeth are re-curved to prevent prey from escaping easily. Its jaws are even designed like a snake to an extent, even being able to open its mouth wide and swallow some large prey.
Tamamitsune are carnivorous in nature, feeding mainly on fish and other small prey; However Tamamitsune are known to feed on larger prey occasionally like Kelbi. Though Tamamitsune are capable predators, they must compete with other large predatory monsters like Zinogre, Lagiacrus, Nargacuga, and Plesioth.
Tamamitsune are able to breath bubbles at its enemies and are also able to produce these bubbles in its fur. It is unknown at this time what the bubbles do, though many believe it hinders the movement of prey. It can also fire pressurized jets of water from its mouth, much like Plesioth.
PS. Info is from Translated MHX Information on Tamamitsune